I just put in a obd1 p72 ecu chipped with crome with obd2->obd1 harness onto my 1999 gsr.

When i start the car the idle totally fluctuates between 1500-1800 and slowly the idle goes from 1500-1550.

There is also a solid CEL on at all times. I tried pulling the code like i normally would with the obd2 ecu. With the paperclip trick but the light just stayed solid.

Does anyone know what the two problems are coming from? Could it be the harness is messed up or is it the ecu that is fked up. Please let me know you guys.

Oh yeah also when i put in my obd2 ecu and remove the harness and obd1 ecu. The CEL dsiappears and I idle like i normally would again.

 

that chip has a bad bin on it...someone probably wrote the bin to the eprom and didnt bother to verify after....of course this is assuming it was chiped correctly
if u have an eprom writer i can send you a legit program of your choice....im also a reseller for hyperducktuning

 

some people said it could be a bad ecu. could this be a problem. thanks for the offer but i don't know have the hardware to program the ecu.

 

ttt.

 

just got new chipped ecu and new conversion harness. i still have a SOLID CEL. i can't pull the code to see what it is because when i do paperclip trick the CEL remains solid. (doesn't blink at all)

 

bumpizzle i need a fixizzle

 

I don't know how good that conversion harness is, but here's what I know about OBD-1...

Does the CEL do ANYTHING when you jumper your SCS connector? Code zero means a bad ECU, but that's indicated by the CEL going OFF when you put in the jumper.

Make sure your SCS connector is connected properly. One side to ECU terminal D4 & other side to ground. Instead of using a paperclip, you could just backpin terminal D4 with a ground wire.

ECU terminal A9 should be the IACV, but I think(?) the whole operation of the IACV is different between OBD-1 & OBD-2. If you want to use an OBD-1 ECU you might need to install OBD-1 IACV & FITV. (Unless the chip is programmed to deal with the differences??)